A prominent reformer at Vietnam’s Labor Ministry was arrested last month and charged with leaking state secrets, state media reported Thursday.

Nguyen Van Binh, director general of the ministry’s legal department, was arrested on April 24 and prosecuted for “having deliberately disclosed State secrets” under Article 337 of Vietnam’s Penal Code, according to Voice of Vietnam.

The 88 Project, a nonprofit focusing on free speech in Vietnam, said Binh’s phone has been inactive since April 15.

While the state broadcaster did not give further details about the arrest, The 88 Project said Binh’s arrest is part of a larger effort to crack down on human rights.

“The arrest of Nguyen Van Binh is part of a new wave of repression sweeping through Vietnam,” the group said in a report issued days before state media confirmed the arrest.

The group noted that Binh had been pushing the government to ratify International Labour Organization Convention 87 — which gives workers the right to form unions.

Vietnam has only a single state-affiliated union, and foreign trade partners such as Canada have for years been pushing Hanoi to ratify the 75-year-old treaty.

Before his arrest, Binh, a lawyer and unionist who had worked at the ILO, had long pushed to improve worker rights.

The group linked Binh’s arrest to Directive 24, a purported leaked Communist Party document that calls for “prevent[ing] the establishment of labor organizations” and deeper control of state security. The text was made public in March by The 88 Project, which termed it a “war on human rights.”

News of Binh’s arrest came just one day after the U.S. Department of Commerce held a hearing to consider whether to recognize Vietnam's economy as a "market economy."

The upgrade would take Vietnam off a list of 12 countries, including North Korea and China, whose heavy state influence marks them as planned economies. Were it to be removed from the list, Vietnam would be able to access U.S. trade preferences.

U.S. steelmakers, among others, have opposed the move — as have advocacy groups who say the country has fallen far short of protecting workers’ rights. A decision is expected to be issued in late July.

At Wednesday’s virtual public hearing, lawyers representing Vietnam argued that the country met all six of the Commerce Department’s criteria, including the right to collective bargaining.

"Vietnam has demonstrated that its performance on these statutory factors is as good, or often better, than other countries that have previously been granted market economy status," said attorney Eric Emerson, Reuters reported.

But Human Rights watch disputed that claim, saying in a statement that Hanoi’s labor laws fell far short of international standards.

“It’s patently false to claim that Vietnamese workers can organize unions or that their wages are the result of free bargaining between labor and management,” said John Sifton, Asia advocacy director at Human Rights Watch.

“Not a single independent union exists in Vietnam and no working legal frameworks exist for unions to be created or for workers to enforce labor rights.”